This invention relates to material handling apparatus and more particularly to a pallet molded of synthetic resin material or the like adapted to form part of a container for transporting, supporting, and storing a load of fine granular, particulate, powdered or other fluidizable material, and for fluidized unloading of the load from the container.
The pallet of this invention represents an improvement over the container disclosed in the coassigned U.S. Pat. No. 4,007,694, and commercially available from the assignee of this invention, Semi-Bulk Systems, Inc. of St. Louis, Missouris under their registered trademark AIR PALLET. The pallet disclosed in the above-noted patent is generally circular, as viewed from above, having a number of legs spaced for the entrance of the tines of a forklift from any of four directions. The pallet has a peripheral wall extending around the pallet and an upwardly facing deck supported by the peripheral wall for supporting the load. The deck slopes downwardly toward one side of the pallet and is adapted to have a porous diaphragm of cloth or the like secured thereto with the diaphragm covering the deck. An outlet opening is provided in the peripheral wall of this prior art pallet above the level of the deck at the lowest side thereof through which the powdered load may be discharged or unloaded. An inlet opening also extends through the peripheral wall for introducing compressed air into the space between the diaphragm and the deck. The compressed air flows upwardly through the porous diaphragm for fluidizing the powdered load bearing against the diaphragm.
The diaphragm of this prior art container was secured to the pallet by a spline held in place within a groove by means of staples driven into the pallet. The spline merely distributed the loading of the diaphragm to the staples. However, upon fluidizing the load in this prior pallet, the air pressure beneath the diaphragm would, on occasion, apply tension loading on the staples and pull them free of the pallet thereby releasing the diaphragm and preventing fluidization of the remaining portion of the load. When the diaphragm pulled loose, refurbishment of the pallet was required prior to reuse.